Staircase



FIG. 1 is a perspective view of a staircase in accordance with the present design.

FIG. 2 is a front view for the staircase shown in FIG. 1.

FIG. 3 is a rear view for the staircase shown in FIG. 1.

FIG. 4 is a right side view for the staircase shown in FIG. 1, it being understood that the opposite (left) side not shown is a substantial mirror image thereof.

FIG. 5 is a top view for the staircase shown in FIG. 1.

FIG. 6 is a bottom view for the staircase shown in FIG. 1.

FIG. 7 is a view from beneath the staircase shown in FIG. 1, looking up at it as if from the floor below.

FIG. 8 is a view from above the staircase shown in FIG. 1, looking down at it as if from the floor above.

FIG. 9 is a rear perspective view for the staircase shown in FIG. 1; and,

FIG. 10 is a side perspective view for the staircase shown in FIG. 1.

The dash-dash broken lines in the drawings are included for the purpose of illustrating portions of the staircase and form no part of the claimed design. The dash-dot broken lines in the drawings represent the boundaries of the claimed design and form no part thereof. 

CLAIM The ornamental design for a staircase, as shown and described. 